The prior art camera module is composed of a sensor substrate, a lens holder disposed on the sensor substrate, and a bottomed cylindrical light cutoff shield covering the sensor substrate and the lens holder.
The sensor substrate has on its rear surface a solder ball to be electrically connected to a mounting substrate. The lens holder includes a lens within it.
The light cutoff shield is adhered to a lens holder in such a state that a bottom portion of the light cutoff shield is disposed on the rear surface side of the sensor substrate. The light cutoff shield serves as a magnetic shield.
In the prior art camera module, the upper portion of the lens holder is not covered by the light cutoff shield. Accordingly, there is a problem that the prior art camera module cannot shield electromagnetic waves irradiated from above.
In order to solve the above problem, there is considered a method of vaporizing metal for shielding electromagnetic waves (applying shield coating) on an upper surface of the lens holder exposed from the light cutoff shield. However, in general, the shield coating by vaporization increases the cost. The vaporized metal should be formed so as to be grounded, whereby the cost is further increased.
As another method for solving the above problem, there is considered a method of adhering the light cutoff shield to the lens holder so that the bottom portion of the light cutoff shield is disposed on the upper surface side of the lens holder. However, when the light cutoff shield is disposed thus, there is a problem that the reliability of the camera module is deteriorated.
Namely, the vertical direction position of the lens holder is varied by the focus adjustment of the lens. Accompanying this, the vertical direction position of the light cutoff shield adhered to the lens holder also varies. The variation of the position of the light cutoff shield causes deterioration of the flatness of a surface formed by a lower end portion of the light cutoff shield and a lower end portion of the solder ball of the sensor substrate. Accordingly, when the camera module is mounted on the mounting substrate, in a certain case, only the light cutoff shield is in contact with the mounting substrate, and the solder ball is not in contact with a wiring on the mounting substrate. Alternatively, in another case, only the solder ball is in contact with the wiring on the mounting substrate, and the light cutoff shield is not in contact with the mounting substrate, so that the light cutoff shield is not operated as a magnetic shield. When the flatness of the surface formed by the lower end portion of the light cutoff shield and the lower end portion of the solder ball is deteriorated, the reliability of the camera module is deteriorated.